With certain applications of time measurement methods, it can occur that a region of an echo curve which is selected for determining the offset of the echo curve is no longer free from interference, such as free from noise. In this case, the value of the offset is wrongly determined and deviates from the real offset value. A deviation from this actually present offset value can lead to the occurrence of inaccuracies or errors when determining a reference line or a normal value. These inaccuracies may lead in turn to inaccuracies when determining a measured value relating to this reference line.
In document DE 100 44 769 A1, a method is described for measuring distance by means of a signal, wherein an echo signal is received by a receiver device or by a receiving device, said echo signal being superimposed with a first reference pulse and wherein the echo signal is compared with a second reference signal that has a second reference pulse for the determination of a signal transit time.
Often, with measuring methods for the measurement of filling levels, a reference curve which must be determined and stored in advance is used in order to correct a newly read-in curve. An empty tank may be necessary for determining this reference curve, said tank having to be emptied artificially from time to time for adjusting the reference curve.
Accordingly, it may be a motivation for the present invention to enable more efficient measuring of signal transit times.